Santa Clara University law professor Eric Goldman takes a look at what happens when Google enters its own ad auctions—and doesn't like what he finds. A version of this article originally appeared at Search Engine Land.

Introduction

Many publishers run "house ads" to self-promote their own offerings. Google does too. However, Google differs from most publishers because it auctions ad space on its network. Thus, when Google runs house ads, it simultaneously conducts the auction that it is bidding in—an impermissible conflict of interest. This post explains when Google uses house ads, why I think Google house ads undercut the auction integrity, and what Google should do differently.

Google's House Ads

I have seen Google house ad campaigns in at least three circumstances:

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1) Occasionally, Google uses AdWords ads to explain problematic organic search results. Two prominent examples are the search results for "Jew," which regularly displays an anti-Semitic organization as a top organic result, and "Michelle Obama," which last year displayed an offensive image as a top organic result. In these situations, Google runs an AdWords ad that links to an explanation of its search algorithms.

In some cases, Google's house ads appear in ad spots unavailable to other advertisers, such as its promotion of Nexus One on its home page. Barry Schwartz has catalogued examples of Google's home page advertisements. This post focuses on house ads in AdWords, but I will come back to these non-traditional ad spots in a bit.

3) As a type of public service announcement, Google runs house ads in AdWords during crises to promote a crisis response page-mostly recently, in response to the BP oil spill.

Why Google House Ads in AdWords Are Problematic

Google characterizes AdWords is an advertising auction system for advertisers to bid on keywords against each other. Google runs these auctions as the auctioneer-a term Google doesn't use and presumably would avoid, but an appropriate descriptor of Google's proclaimed role vis-à-vis advertisers. Because Google merely conducts the auctions for advertisers, Google argues that it does not set AdWords advertising prices; instead, the prices are set by the market (i.e., the collection of advertisers' auction bids). Google's positioning as an auction conductor has emerged as a central defense to the increasing antitrust attention being paid to Google's remarkable share of the search advertising market.

However, Google's positioning breaks down when Google buys house ads via AdWords. In those situations, Google is both running the auction and bidding in that auction as an advertiser. The conflicts of interest in this situation should be self-evident, but let's look at them in more detail.

Google Can Win Every Auction It Enters.

When Google runs a house ad in AdWords, it does not cost Google anything out-of-pocket. However, those clicks aren't necessarily "free" because Google's ads have opportunity costs. Clicks on Google's house ads may siphon away clicks from revenue-generating ads, which may reduce Google's revenue from the bidded term.

Google's spokesperson told me that Google's house ads "are subject to internal marketing budgets." I assume this means that a Google department running house ads must "pay" for its clicks by transferring money from its department budget to a different Google department. In theory, the scarcity of marketing budgets forces Google departments running house ads to internalize the opportunity cost, even if no cash changes hands.

However, I don't believe this cures the defects in auction integrity for at least four reasons. First, Google's behavior lacks any auditability or verifiability; as outsiders, we have no idea what Google is doing under the hood. Second, Google has access to better information to optimize its bidding than any other bidder. That information may not be functionally available to individual employees placing auction bids, but because of the first point (lack of auditability/verifiability), we as outsiders don't know that either. Third, because all Google bids just involve internal funds transfers and no out-of-pocket cash payments, Google can easily increase departmental budgets to enable more aggressive bidding-after all, if no cash changes hands, it's just funny money anyway. Fourth, actual ad placement depends on ad quality scores, and Google has acknowledged that it has "exceptionally high Quality Scores" which should automatically give it a bidding advantage over everyone else. And, once again, no one else can audit or verify Google's self-designated ad quality scores.

As a result, Google's advantages over other bidders should allow it to "win" its auctions whenever it decides to bid.

Google's Bids Can Affect the Prices Paid by Its Advertisers.

As far as I know, Google has never publicly addressed how its house ads affect the prices paid by other bidders. In response to my inquiry, the Google spokesperson opaquely informed me that "Google's ads are not guaranteed to appear in any given spot. How this affects CPCs depends on the quality scores and bids of others in the auction." I interpret this to mean that Google's presence in the auction could affect the CPCs paid by other bidders. Let's take a look at how this might happen.

Google auctions aren't winner-take-all. Instead, Google runs a "second-price auction." As Google describes it, each advertiser-bidder pays "the minimum amount necessary to maintain their position on the page," which is the amount bid by the next-lowest bidder. To illustrate this, assume a keyword with the following bids:

Pursuant to the second-price auction, Bidder 1 pays $0.75 per click (i.e., the amount that Bidder 2 bid). After all, if Bidder 1 had only bid $0.75 per click, it still would have shown up as the top bidder. Bidder 2 pays $0.50 per click, the amount required to stay in the second position.

[Note: my examples assume that the bidders have the same ad quality scores and that one bidder's presence or behavior does not cause Google to recompute the ad quality scores of other bidders.]

Now, consider what happens when Google enters a bid in this auction.

Google bids more than $1.25 per click [the result is the same if Google bids $1.25 or $1M per click]
Bidder 1 bids $1.25 per click
Bidder 2 bids $0.75 per click
Bidder 3 bids $0.50 per click

I'll just focus on Bidder 1, who was getting first position for $0.75 per click before Google's entrance. Due to Google's entry into the auction, Bidder 1 now pays the same per-click amount to show up in second position rather than first.

Bidder 1's reduced position may change the commercial value of the consumers who investigate the links. That is, the consumer who clicks on the second ad may have a different profit potential than the person who clicks on the first ad. In some cases, clicks on lower-placed ads may be more profitable per click, so we don't know a priori if this is good or bad for any particular advertiser.

We can anticipate that Bidder 1's lower position will reduce the overall volume of clicks it gets at that price. A second position ad usually gets substantially fewer clicks than the first position ad. Further, if Google syndicates the house ad via AdSense, then Bidder 1's ads may no longer be syndicated in AdSense (for example, if Google syndicates only 1 ad via AdSense). [Note: when Google house ads are syndicated, Google pays the AdSense publisher for clicks out-of-pocket-but presumably Google pays a wholesale discounted price, while all other advertisers must pay the 100% retail price.]

Naturally, some advertisers will seek to reclaim their prior ad position by increasing their bids. Indeed, Google's AdWords tools will automatically encourage advertisers to pay more to generate more clicks. For advertisers using Google's automated bidding tool (sometimes called the "Budget Optimizer"), Google may automatically increase an advertiser's bid to increase click volume. Thus, Google's entry into the auction could cause other bidders to increase their bid amounts in a variety of ways.

Let's revisit my discussion about Google's opportunity cost of clicks on house ads. If the other bidders' prices stay the same and Google siphons away some clicks from them, Google's ads have a clear opportunity cost. However, if Google's entry into the auction prompts other bidders to pay more, some or all of that opportunity cost will be made up by increased revenue on the remaining clicks. It's even possible that Google's house ads could create net new profit. From an auction integrity standpoint, it's unacceptable for Google's entry into the auction to affect the prices bid or paid by other bidders (its advertisers), whether Google's profits increase or decrease.

Alternatives for Google

Google's spokesperson told me that "[l]ike hundreds of thousands of other businesses, we believe in the value of search marketing to connect with web users." That makes sense to me, and I encourage Google to go for it-just not by bidding against its other advertisers. Google can benefit from keyword advertising other ways without undermining its auctions' integrity.

First, Google can buy keyword ads from third parties. Apparently Google already does this regularly, including buying ads from Yahoo and Bing. See this comprehensive survey as well as this example.

Second, as Google already does on occasion, Google can create new ad units outside AdWords exclusively for house ads. Running ads in a separate ad unit would obviate the need for Google to compete with advertisers in an auction, although I imagine some advertisers still will be annoyed by any click siphoning.

Third, Google could refuse all advertiser bids on terms that Google chooses to use for house ads. Advertisers wouldn't be thrilled if Google did this either, but it would maintain the auction integrity for those terms. This would be the most expeditious way for Google to handle objectionable organic search results, although creating a new unit outside AdWords would work as well.

Conclusion

I feel a little silly writing nearly 2,000 words explaining why auctioneers should not bid in the auctions they run. We all already knew that. Yet, Google apparently violates this basic rule every time it runs house ads in AdWords auctions. Google should fix this-and restore integrity to its AdWords auctions-by no longer competing with its advertisers in those auctions.

Google's Response

A Google spokesperson sent me this response:

"As we've always said, all search engines run ads to inform users about services that they provide. Google is no exception to this practice. We believe in the value of our advertising platform and use it in the same way that other advertisers do."

About the author: Eric Goldman is an Associate Professor of Law and Director of the
High Tech Law Institute at Santa Clara University School of Law. His research and teaching focuses on Internet, IP and marketing law topics, and he blogs on those topics at the Technology & Marketing Law Blog.